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Fisiologia
Respiratória
Table 36-1. Stimuli affecting the respiratory center.
Chemical control
CO2 (via CSF and brain interstitial fluid H+ concentration)
O2
H+
⎫⎬⎭
(via carotid and aortic bodies)
Nonchemical control
Vagal afferents from receptors in the airways and lungs
Afferents from the pons, hypothalamus, and limbic system
Afferents from proprioceptors
Afferents from baroreceptors: arterial, atrial, ventricular, pulmonary
Table 36-2. Airway and lung receptors.1
Vagal
Innervation Type
Location in
Interstitium Stimulus Response
Myelinated Slowly adapting Among airway
smooth muscle
cells(?)
Lung inflation Inspiratory time shortening
Hering-Breuer inflation and
deflation reflexes
Bronchodilation
Tachycardia
Rapidly adapting Among airway
epithelial cells
Lung hyperinflation
Exogenous and endogenous
substances (eg, histamine,
prostaglandins)
Hyperpnea
Cough
Bronchoconstriction
Mucus secretion
Unmyelinated
C fibers
Pulmonary C fibers
Bronchial C fibers
Close to blood
vessels
Lung hyperinflation
Exogenous and endogenous
substances (eg, capsaicin,
bradykinin, serotonin)
Apnea followed by rapid
breathing
Bronchoconstriction
Bradycardia
Hypotension
Mucus secretion1 Modified and reproduced, with permission, from Berger AJ, Hornbein TF: Control of respiration. In: Textbook of
Physiology, 21st ed. Vol. 2. Patton HD et al (editors). Saunders, 1989.
Figure 36-1. Respiratory neurons in the brain stem. Dorsal view of brain stem; cerebellum removed. The
effects of various lesions and brain stem transections are also shown. The spirometer tracings at the right
indicate the depth and rate of breathing. DRG, dorsal group of respiratory neurons; VRG, ventral group of
respiratory neurons; NPBL, nucleus parabrachialis (pneumotaxic center); 4th vent, fourth ventricle; IC,
inferior colliculus; CP, middle cerebellar peduncle. The roman numerals identify cranial nerves.
(Modified and reproduced, with permission, from Mitchell RA, Berger A: State of the art: Review of
neural regulation of respiration. Am Rev Respir Dis 1975;111:206.)
Figure 36-7. Rostral (R) and caudal (C) chemosensitive areas on
the ventral surface of the medulla
Figure 36-5. Organization of the carotid body. Type I (glomus) cells contain catecholamines. When exposed to hypoxia,
they release their catecholamines, which stimulate the cup-like endings of the carotid sinus nerve fibers in the
glossopharyngeal nerve. The glia-like type II cells surround the type I cells and probably have a sustentacular function.